Mixer drum and construction method therefor



Dec. 23, 1958 J. A. MASEK MIXER DRUM AND CONSTRUCTION METHOD THEREFOR 2 Sheets-Sheet 1 Filed Oct. 12. 1955 mA N flu ATTORNEY Dec. 23, 1958 J. A. M'ASEK 2,865,616

MIXER DRUM AND CONSTRUCTION METHOD THEREFOR Filed Oct. 12. 1955 2 Sheets-Sheet 2 M IN VEN TOR.

BY JOHN A. MASEK Mum A'rrgauzv United States Patent MIXER DRUM AND CONSTRUCTION METHOD THEREFOR John A. Masek, Milwaukee, Wis., assignor to The T. L.

Smith Company, Milwaukee, Wis., a corporation of Wisconsin This invention relates to a new concrete mixer drum construction and to the method of fabricating the drum. The drum herein described is particularly useful with respect to truck mixers, but the invention is not limited thereto.

Drums of this type are quite large and have always presented manufacturing problems and have occasioned difliculties in use from time to time. The drum has generally been made of a forward drum section having a discharge cone section fixed thereto. These sections and their associated blades, charging cone, etc. were fabricated as sub-assemblies before bringing them together as a completed drum. The many required welds, both longitudinal and circumferential, not infrequently warped the drum, requiring re-machining of the drip ring and the roller track. Furthermore, the stresses concentrated on the roller track often occasioned difliculties in the field.

The present drum is built up from sub-assemblies which eliminate most of the difiiculties previously encountered in drums of this type while obtaining a number of advantages over prior constructions. With the present construction of drum capacity can be varied by changing the size of but one sub-assembly.

Another advantage is that the drum is reinforced under the roller track to better withstand the strains found in use.

The principal object of this invention is to provide a simplified and stronger construction of a mixer drum. Another object is to provide a simple method of fabrieating a mixer drum. 1

Other objects and advantages Will be pointed out in, or be apparent from, the specification and claims, as will obvious modifications of the single embodiment shown in the drawings in which:

Fig. 1 is a side view of a truck mixer having a drum fabricated in accordance with this invention;

Fig. 2 is a section of the drum shown in Fig. 1 and illustrates the double thickness of the telescopic joint between the front and rear sections of the discharge cone portion of the drum;

Fig. 3 is an enlarged fragmentary view of the telescopic joint showing the manner of welding the cone section and of mounting the roller track on the double thickness section of the resulting cone wall; and

Fig. 4 is a view of the drum with part of the shell removed to show the blading in the various sections thereof.

Fig. 1 shows a high capacity mixer drum mounted on a truck in the usual manner. The drum is made up of a number of sections which, in turn, make up sub-assemblies. The forward or bowl portion 8 is comprised of dished section 10 and frusto conical section 12 which can be standard for all drum sizes and can, therefore, be manufactured in quantity. The middle section 14 is optional, being used where larger drum capacities are desired and the axial length of the middle section can be varied to vary the drum capacity. In this manner all truck drum sizes can be made by varying only. the middle section. The discharge cone portion 16 is made up of a front cone section 18 and a rear cone section 20. The sections 18 and 20 are standard for all drum sizes and can be manufactured in quantity.

in the base ofthe bowl portion 8 each of sections 10 and 12 are fabricated separately and then welded together. The blades mounted in sections 10 and 12 of bowl portion 8 are aligned with each other and are welded together at the joint between the sections as at 13 (Fig. 4). Next the discharge portion 16 of the drum' may be fabricated. The rear section is made'up from a single arcuate plate formed to make the frusto conical section. The blades and the charging cone 19 may then be mounted inside the rear section while the roller track 22, which rests on the support rollers 21, 21 in the finished unit, is mounted on the outside of the section adjacent its forward edge and the drip ring 24 is mounted on the rear opening of the rear section. The rear section 20 is adapted to telescope over the front section 18 as shown in Figs. 2 and 3 to give a double thickness underlying the roller track 22. Welds 26, 28 complete the joint. The blades can be mounted in section 18 before or after the sections 18 and 20 are connected. When the blades are installed before the connection is made the blades in sections 18 and 20 are aligned and welded together as at 15 (Fig. 4).

The discharge portion 16 and the bowl portion 8 are designed so the blades match with no middle section 14 between the portions. This gives the small size drum. Various sizes of the middle section can be employed to increase the drum capacity. I find three additional drum sizes easily obtained by employing middle sections each of which successively requires the discharge portion to be rotated turn. The middle section is provided with blades to line up with the blades in section 12 of the bowl portion and section 18 of the discharge portion of the drum for welding as at 23 and 25 (Fig. 4). It will be appreciated that the present construction permits considerable manufacturing economies through mass production of all the complex drum sections. The only variable is the middle section which is the easiest to fabricate.

The discharge portion of the drum is much easier to fabricate in two sections as described above. This makes it much easier to weld the blading on the inside of the two sections and makes it a simpler matter to mount and remachine the roller track 22 and the drip ring 24 should such machining be necessary after mounting these parts on the rear section. Since the present construction results in a double thickness under the roller track 22, the unit is capable of better handling of the concentrated stresses at this point. In practice I allow about two inches of overlap (the distance x in Fig. 3) to distribute the load over a large area. This overlap may be varied, of course, in various situations depending upon the loads, etc.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. A mixer drum comprising a bowl portion having a dished section and a frusto-conical section, blading mounted in each of said sections with the blading in one section aligned with the blading in the other, a discharge portion terminating in a-discharge opening and having a forward and a rear section of frusto-conical shape, said forward and rear sections being telescoped one into the other to provide a joint, a roller track mounted on said discharge portion at said joint whereby the drum has a double thickness under the track, and blading mounted in each of said forward and rear sections with the blading in one section aligned with the blading in the other, said bowl and discharge portions being connected together with the blading in the frustoconical section of said bowl portion aligned with the blading in the forward section of said discharge portion.

2. A mixer drum according to claim 1' in which bowl and discharge portions are connected by a generally cylindrical middle section having blading mounted therein in alignment with the blading in said bowl and discharge portions.

3. A mixer drum including a generally frusto-conical discharge portion terminating in a discharge opening,

said portion including a forward and rear section with both sections being of frusto-conical shape, said sections being telescoped one into the other to provide a joint and a roller track mounted on said portion at the joint whereby the drum wall has a double thickness under the track, said discharge portion having blading mounted in each of said forward and said rearward sections with the blading in one section aligned with the blading in the other.

References Cited in the file of this patent UNITED STATES PATENTS 1,165,905 Reimann Dec. 28, 1915 2,438,555 Gilson Mar. 30, 1948 2,556,034 Gerst June 5, 1951 FOREIGN PATENTS 76,956 Austria June 25, 1919 

